Mayer Brown offices in Washington, D.C. Photo: Diego M. Radzinschi/ NLJ

The former co-leader of Mayer Brown's national security practice will be the Trump administration's nominee to serve as the U.S. ambassador to Russia, the White House said Friday.

John Sullivan

John J. Sullivan has been serving as the U.S. Senate-confirmed second-in-command at the U.S. State Department since mid-2017. Sullivan would succeed Jon Huntsman as ambassador. Huntsman, who resigned in August, is reportedly mulling a run as governor of Utah.

Sullivan briefly served as the acting secretary of state in 2018 after the departure of Rex Tillerson, the former Exxon chief executive. Sullivan has held senior posts, earlier in his career, at various federal agencies, including the Justice Department and Commerce Department, the White House said.

As the No. 2 at State, Sullivan, "leads a pair of ongoing dialogues with Russia—focused on counterterrorism and strategic security—and he worked on issues involving that country in prior roles in government and in private legal practice," The Wall Street Journal reported.

Sullivan resigned from his Mayer Brown partnership in 2017 on his confirmation as deputy secretary of state. Sullivan had been a partner at Mayer Brown since 2012. His clients included Deloitte Touche Tohmatsu and Medtronic Inc. Sullivan reported receiving $318,000 in salary and bonus from the firm in 2016 and 2017, according to a financial disclosure form he filed as part of his nomination as deputy secretary.

Mayer Brown's national security practice is led by Rajesh De, a former general counsel to the National Security Agency. De also serves as the law firm's managing partner in Washington, D.C. De was not immediately reached for comment Friday.

Trump's intent to nominate Sullivan marks the latest former Big Law partner to win a nod to serve as a U.S. ambassador. Christopher Landau, formerly at Quinn Emanuel Urquhart & Sullivan, was confirmed this year as ambassador to Mexico, and A.B. Culvahouse Jr., formerly chairman of O'Melveny & Myers, was confirmed as ambassador to Australia. The nomination of Sullivan & Cromwell's Michael DeSombre for U.S. ambassador to Thailand is pending in the U.S. Senate.

Sullivan clerked for Justice David Souter during the 1990-1991 Supreme Court term, the first for the newly appointed justice. His co-clerks that year were Meir Feder, Paul Salamanca and Peter Spiro. Feder's now a New York-based partner at Jones Day. Salamanca teaches at University of Kentucky College of Law, and Spiro teaches at Temple University Beasley School of Law.

Sullivan met his future wife, Grace Rodriguez, at Columbia Law School. Rodriguez is a Washington-based King & Spalding partner, where she focuses on special matters and government investigations. Sullivan and Rodriguez were editors at the Columbia Law Review.

"I still use the skills that I developed in law school," Sullivan told Columbia Law in an interview in 2017. "The tricks I learned and the way I did things, I still do the same way—whether it's for a meeting or other activities where I'm given lots of information and have to be prepared to answer questions, and some of those questions I may not be given in advance."

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